Kaposi's sarcoma associated herpesvirus (KSHV) or human herpesvirus 8 (HHV-8) was found in 100% of Kaposi's sarcoma and many body cavity-based lymphomas. It has been hypothesized that KSHV causes these malignancies. KSHV DNA can persist in a latent episomal form and a linear replicative form. The episomal form has been shown to be maintained by the cellular DNA polymerase. It is hypothesized that the episomal viral DNA is maintained by a specific viral origin of replication (ori P) and a DNA binding protein termed trans-activator which is involved in replication of the viral episome. Three aims are proposed. The first is to identify ori P of KSHV. The second is to map the initiation site and direction of replication. The third aim is to search for the transactivator. This study should lead to better understanding of latency.